Valid Sunday September 13, 2020 through Monday September 14, 2020

This advisory is in effect through Monday afternoon. AQMD will issue an update if additional information becomes available.

Two major local wildfires as well as wildfires in Northern and Central California are affecting air quality in the region. A wildfire named the Bobcat Fire is burning north of Azusa and Monrovia in the Angeles National Forest. As of 8:00 AM on Sunday, the burn area was approximately 31,991 acres with 6% con- tainment. Current information on the Bobcat Fire can be found on the Incident Information System (Inci- Web) at https://inciweb.nwcg.gov/incident/7152.

A wildfire named the El Dorado Fire is burning in the near Yucaipa in San Bernardino County. As of 7:30 AM on Sunday, the burn area was reported at 14,283 acres with 41% containment. Current information on the El Dorado Fire can be found on the Incident Information System at: https://inciweb.nwcg.gov/incident/7148/.

Smoke from fires in Northern and Central California is also being transported south and may impact the South Coast Air Basin and Coachella Valley.

Past and Current Smoke and Ash Impacts

The Bobcat Fire is producing substantial amounts of smoke on Sunday morning based on satellite and webcam imagery. The El Dorado Fire is also still producing smoke that is visible on satellite and webcam imagery. Falling ash has been reported downwind of the Bobcat Fire throughout the South Coast Air Basin. Smoke from fires in Northern and Central California is still present in upper levels of the atmosphere this morning.

South Coast AQMD’s temporary monitors deployed in Azusa, near the Bobcat fire, and Redlands, near the El Dorado Fire, as well as South Coast AQMD’s monitors in Glendora and Upland have measured Air Quality Index (AQI) values in the Unhealthy to Very Unhealthy categories since yesterday evening. The fire is also producing ash particles that are small enough to be detected by South Coast AQMD’s PM10 monitors in addition to the smoke detected by the PM2.5 monitors. Smoke impacts have been widespread, with elevated concentrations recorded far from the wildfires. South Coast AQMD’s monitors throughout the rest of the South Coast Air Basin and Coachella Valley have measured hourly values in the Moderate to Unhealthy AQI categories. Low-cost sensors in Los Angeles, the , the , the Santa Monica Mountains, Long Beach, and portions of the have been in the Unhealthy to Hazardous AQI categories. Visit https://www.aqmd.gov/aqdata to view current air quality conditions.

In any area impacted by smoke: If you smell smoke or see ash due to a wildfire, limit your exposure by remaining indoors with windows and doors closed or seeking alternate shelter, and avoiding vigorous physical activity. For more tips on protecting yourself during a wildfire, see South Coast AQMD’s Wildfire Smoke & Ash Health & Safety Tips page: http://www.aqmd.gov/wildfire-health-info-smoke-tips

1 Forecasted Smoke and Ash Impacts

Most of the South Coast AQMD jurisdiction will experience smoke impacts with the highest AQI values occurring in direct proximity to the Bobcat and El Dorado Fires. Smoke transported from fires in Central and Northern California may also contribute to widespread elevated particulate matter (PM2.5 and PM10) concentrations. Smoke and ash impacts will be highly variable in both timing and location through Mon- day.

• Sunday afternoon through Sunday evening: Smoke from the Bobcat and El Dorado fires will impact areas in Los Angeles, Orange, Riverside, and San Bernardino Counties in the early afternoon. As the day progresses, some clearing is expected in Los Angeles and Orange counties, with the bulk of the smoke moving to the east and northeast into Riverside and San Bernardino Counties during the late afternoon through the evening. Smoke will persist in the in Los Angeles County throughout this period.

• Overnight Sunday through Monday morning: Winds will be light and variable overnight. Areas south of the Bobcat fire along the I-10 corridor from Glendale to Rancho Cucamonga will likely see the highest particulate matter levels as smoke is likely to remain closer to the ground overnight. Smoke impacts from the El Dorado Fire are predicted for western Riverside and San Bernardino Counties and the Coachella Valley, with the highest particulate matter levels likely between San Bernardino and Banning. Other areas of the South Coast Air Basin could also see smoke impacts on Monday morning to a lesser extent.

• Monday afternoon: Onshore winds will start after noon and will likely move smoke to the north and northeast into the mountains of Los Angeles, Riverside, and San Bernardino Counties and out of the South Coast Air Basin. Modest smoke impacts may persist throughout the rest of the South Coast Air Basin and Coachella Valley due to smoke from the Northern and Central California fires.

Overall, meteorological conditions will bring smoke and ash into portions of Los Angeles, Orange, River- side, and San Bernardino Counties. Unhealthy or higher AQI levels due to PM2.5 and PM10 concentra- tions are possible in areas of direct smoke impacts. Impacts will be highly variable throughout the day, impacting different parts of the region at different times.

Areas of direct impacts and poor air quality may include portions of:

• Los Angeles County: Central Los Angeles (Area 1), Northwest Coastal LA County (Area 2), Southwest Coastal LA County (Area 3), South Coastal LA (Area 4), Southeast LA County (Area 5), West San Fernando Valley (Area 6), East San Fernando Valley (Area 7), West San Gabriel Valley (Area 8), East San Gabriel Valley (Area 9), Pomona-Walnut Valley (Area 10), South San Gabriel Valley (Area 11), South Central Los Angeles County (Area 12), Santa Clarita Valley (Area 13), San Gabriel Mountains (Area 15)

• Orange County: Northern Orange County (Area 16), Central Orange County (Area 17), North Coastal Orange Count (Area 18), Saddleback Valley (Area 19), Central Coastal Orange Cou (Area 20), Capis- trano Valley (Area 21)

• Riverside County: Corona-Norco (Area 22), Metropolitan Riverside County (Area 23), Perris Valley (Area 24), Lake Elsinore (Area 25), Temecula Valley (Area 26), Anza Valley (Area 27), Hemet-San Jacinto Valley (Area 28), San Gorgonio Pass (Area 29), Coachella Valley (Area 30), East Riverside County (Area 31)

• San Bernardino County: Northwest (Area 32), Southwest San Bernardino Val- ley (Area 33), Central San Bernardino Valley (Area 34), East San Bernardino Valley (Area 35), West San Bernardino Mountains (Area 36), Central San Bernardino Mountains (Area 37), East San Bernardi- no Mountains (Area 38)

2 South Coast AQMD Advisory updates can be found at the following link: http://www.aqmd.gov/advisory

To subscribe to air quality alerts, advisories and forecasts by email, go to http://AirAlerts.org

To view current air quality conditions by region in an interactive map, see http://www.aqmd.gov/aqimap

For real-time air quality information, maps, notifications and health alerts in your area, download our award-winning South Coast AQMD app at: http://www.aqmd.gov/mobileapp

Air quality forecasts are available at http://www.aqmd.gov/forecast

For a map of South Coast AQMD Forecast Areas, see http://www.aqmd.gov/ForecastAreas

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